Yep, until now I knew so little about the Mayan number system that I never even noticed I was staring right at it every time I made a purchase. It wasn't until this weekend's trip to Copán when our tour guide said "Since you've been living in Guatemala all this time, you must already know that the Mayan numbers are written on all their currency," that I awkwardly said "Um, actually no" and whipped out some cash to see what I'd been missing all this time.
The Mayans' number system consists of dots, lines, and shells. They could write all the way up to 19 using just these figures. After 19, placement determined a number's value (just like we use today -- we know that 92 really means nine 10s and two 1's because that's where those numbers are placed). However, while our placements have values of 10s (the 10s place, 10x10=100s place, 10x10x10=1000s place), the Mayan numeric system uses values of 20 (the 20s place, the 20x20=400s place, the 20x20x20=8000s place).
A dot means 1.
A line means 5.
A shell means zero. The Maya were one of the only ancient civilizations to understand the concept of zero.
So, onto the money!
Lo and behold, the quetzales bills DO have the Mayan numbers written on them! I'd just never thought for a second that those shapes were anything more than decor. Check it out though!
That green dot just to the right of the figure's head. A dot means 1. One quetzal bill!
Again to the right of the figure's head: a dot over a shell. Placeholding goes vertically in the Mayan numeric system. So, shell means zero in the ones place. Dot means one in the 20s place. Zero ones and one twenty. Twenty. Twenty quetzales bill!
Same thing here. Top right corner. Line over a shell. Shell means zero in the ones place. Line means five in the 20s place. Zero ones and five twenties. One hundred. Ta da!
You're impressed, aren't you?
P.S. Thanks goes out to Sam who was incredibly embarrassed that I was taking these photos in the middle of Bagel Barn, but she kept sharing a table with me anyway. That's friendship. :)